The goal of this project is to characterize the structure of bacterial capsular polysaccharides related to invasive disease in humans; the bacteria of concern are either those that are directly pathogenic or those that crossreact with pathogenic organisms. Additionally, work is underway to develop methods to characterize and to characterize the solution conformations of bacterial polysaccharides, beginning with smaller structural units. The capsular polysaccharides from Salmonella paratyphi has been published this year. The capsular polysaccharide from Moraxella nonliquefaciens has been shown to be identical to that of Group B Neisseria meningitidis. The solution conformational preference of the disaccharide, alpha-L-Rhap(l- 2)-alpha-L-Rhap-(1-OMe) has been extensively probed through NOE NMR methods and molecular mechanics calculations; the NOE methods were able to adequately describe the phi, phi angles about the glycosidic linkage.